For current heat-assisted magnetic recording (HAMR), transition curvature of a magnetic pattern in a recording medium degrades both writing and reading operations in the recording medium and reduces a recording density capability in the recording medium. A circular or curved thermal profile generated by the near field transducer causes the transition curvature when recording head field is essentially spatial-uniform. When thermal profile shrinks for ultra-high-density storage, transition curvature can be a primary cause of reduction of signal-to noise ratio and errors in reading and writing. Due to the thermal profile curvature, grains at different crosstrack positions on a recording track on the recording medium experience different downtrack thermal profiles. At different crosstrack positions, recording is not optimized correspondingly, so writing quality is not saturated. This could be also be explained using a recording time window. In addition, the written track width become modulated by the distance between adjacent transitions down track. Current reader designs are not configured for this mode of operation, since current devices include thin films stacked along downtrack direction. Curved readers, which might be able to accommodate current thermal profiles for ultra-high-density storage, are difficult to manufacture and lack robustness.